It wasn't too long ago that Detroit's two largest automakers were known for large trucks and SUVs while they pumped out less valuable car models to keep production levels up. It was a move that severely hurt their respective brand images. The word "game-changer" is often overused, especially in the media. However, every now and then a product really does change the way consumers see a brand or industry – and that's exactly what Ford (NYSE:F) and General Motors (NYSE:GM) have accomplished with their Fusion and Impala sedans.

Ford's 2014 Fusion. Source: Ford motor company.

Fusion is stunning
Toyota's Camry has long been king of a key American vehicle segment: mid-size sedans. It's a segment that boasts incredible sales with fierce competition between many models that offer great fuel economy and solid value -- something Detroit automakers haven't always been known for. A decade ago, Ford was as close to competing with Toyota's Camry as I am to competing with Usain Bolt. Not very close at all. However, Ford redesigned its Fusion under its new "One Ford" strategy that focused on improving quality, fuel economy, and appearance. The result was stunning, and sales quickly took a bite out of the Camry's success.

Graph by author. Source: company sales reports.

"My design brief to the team was to do an absolute drop-dead gorgeous head-turner," said J. Mays, Ford's head of global design, according to the Detroit Free Press. "And it was to look $10,000-$15,000 more expensive than it is."

Judging by its list of awards, it appears Ford's team accomplished its goal.

  • U.S. News and World Report's "Best Car for the Money."
  • 2013 "Green Car of the Year" award from the Los Angeles Auto Show.
  • Kelley Blue Book's "Best Redesigned Vehicle" of the year.
  • U.S. News and World Report's 2013 "Best Cars for Families."
  • U.S. News and World Report's "Best Mid-Size Car" (for three straight years).

Kelly Blue Book also ranked the Fusion second place for its 2013 Best Resale Value Award, a big change from the sedans Ford produced a decade ago. One of the biggest reasons Ford's Fusion has been a hit, aside from its more aggressive exterior, is the EcoBoost engine. The turbocharged engine option has resonated with consumers looking for performance and better fuel economy, and more than half of Fusion's sold have an EcoBoost under the hood. This year the Fusion will probably break 300,000 sales, which only one other Ford vehicle has done in nearly a decade -- America's best-selling truck, the F-150.

Ford's fusion has been a success on many levels; however, Chevy's Impala has done something no other Detroit vehicle has in a long time.

2014 Chevy Impala. Source: General Motors.

Impala is on top
Consumer Reports magazine has been praising domestic automakers more recently and named General Motors' Chevrolet Impala its top-ranking sedan. If you're keeping track, that makes it the first American vehicle to win the sedan's top rank in 20 years -- a huge victory for GM.

"The Impala's performance is one more indicator of an emerging domestic renaissance," says Jake Fisher, director of Consumer Reports automotive testing, in a statement, according to USA Today. "We've seen a number of redesigned American models -- including the Chrysler 300, Ford Escape and Fusion, and Jeep Grand Cherokee -- deliver world-class performance in our tests.

GM still has an uphill battle to fight with consumers after its brand image took a hit during its financial collapse and bankruptcy. However, it's taking necessary steps to improve its vehicles for the long term and is replacing, refreshing, or redesigning 90% of its entire vehicle lineup by the end of 2016 -- the company's most aggressive portfolio turnover, ever.

If the Impala is a preview of what other redesigns will become, import brands beware. The Impala's previous score in the Consumer Reports survey was 63 out of 100, and the recent score jumped to 95 out of 100. It received the high marks for its drastically improved and comfy ride, as well as better handling and spacious cabin. As fuel economy continues to improve with bigger vehicles, Chevy's large sedan could steal market share from the mid-size sedan market, which would make the Impala an even bigger hit.

Ultimately, both of these vehicles have helped Ford and General Motors gain back some market share in segments they were once left for dead in -- these two vehicles are company game-changers. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.